Astronomy Colloquium

As gravitational wave astronomy is taking off it is clear that to understand events detected with Advanced LIGO/Virgo and, in the future, eLISA, we need to build up a better understanding of their source populations: ultracompact binaries containing two stellar remnants. For the bulk of the white dwarf populations, the main source for eLISA, this is done be only through studies in the Milky Way Galaxy. For short-lasting transient phases in these systems synoptic surveys of the Local Universe can shed light on their frequency and environment.  For Advanced LIGO/Virgo sources the final stages of massive stars require a far better understanding. The challenges of developing gravitational wave astrophysics therefore combine the fields of (Galactic) population surveys, synoptic transient surveys such as performed with PTF/ZTF and BlackGEM/MeerLICHT, as well as an understanding of core-collapse supernovae and the physics of fallback accretion disks as well as transistional disks as found in kilonovae events.